Radioactivity may fuel life deep underground and inside other worlds | Hacker News Reader

Radioactivity may fuel life deep underground and inside other worlds

quantamagazine.org

147 pointstheafh37 comments

I was lucky as an undergrad to attend a small lecture by Tommy Gold [1] near the end of his life, where he advocated the ideas described in his book Deep Hot Biosphere. He was often ahead of his time and unafraid to take controversial positions to get there (including the now-accepted, but once derided, phenomenon that we know today as the pulsar).

You might be right again, Tommy.

[1] https://en.wikipedia.org/wiki/Thomas_Gold

Sort of off topic, but I wonder if that idea was part of the inspiration for the origin story of Godzilla, or if it's just a coincidence.

Wasn’t Godzilla a metaphor for the Hiroshima/Nagasaki atom bombs?

yes, godzilla was inspired by nuclear tech

Have you guys ever wondered that if the core fundamental definition of life just starts off as some molecule that self replicates. And that the resulting complexity of life is just errors that happen during replication that are naturally selected to reverse entropy, then could there be other forms of life that are not based on water or carbon?

I get that the carbon atom and water facilitates organic chemistry which results in tons and tons of complicated permutations and configurations of molecules necessary for life but are there other atoms in other conditions that allow permutations that that are equal in complexity? Could some form of life be non-carbon based life be able to exist say in the middle of the sun?

I heard deep in Jupiter's atmosphere is a sea of liquid metal hydrogen. Could a different form of life exist as non-organic chemistry with high pressure liquid hydrogen as an integral part of the self replicating machinery?

Any experts on bio molecular stuff care to weigh in? I'm positive this stuff has been speculated on, but I've also heard that a lot of experts don't consider non-carbon based life without water to be viable or likely simply because organic chemistry facilitates so many complex chemical permutations necessary for life.

Probably hard to form stable molecules and arrangements of molecules with all that plasma and energetic electrons bouncing around

There are chances that it is possible to have some slower form of life at much lower temperatures than on Earth, where the elements H, C, N, O and S still have the major contribution but instead of water some other solvent is used, e.g. hydrocarbons or ammonia.

On the other hand, at very high temperatures, e.g. in the Sun, life is certainly impossible because you cannot have even molecules, much less more complex structures. Everything is a homogeneous mixture of atoms, ions and electrons and any kind of structure would be broken instantly by the agitation of the particles.

If there is any metallic hydrogen on Jupiter, it can be found nowhere close to the atmosphere, but in the core of the planet, at extreme pressures.

There's this cool essay by Isaac Asimov considering viable chemistries for life:

"Not as we know it. The chemistry of life"

http://www.bigear.org/CSMO/HTML/CS09/cs09p05.htm

I was surprised to realise (that besides being a prolific author) that he was a professor of biochemistry.

He ends up with a:

"list of life chemistries, spanning the temperature range from near red heat down to near absolute zero:

1. fluorosilicone in fluorosilicone

2. fluorocarbon in sulfur

3.*nucleic acid/protein (O) in water

4. nucleic acid/protein (N) in ammonia

5. lipid in methane

6. lipid in hydrogen

Of this half dozen, the third only is life-as-we-know-it. Lest you miss it, I've marked it with an asterisk."

The lower temperature chemistries listed above may exist on planets far from the stars.

However the high-temperature chemistries based on fluorine do not have any chances to be found in the nature.

Fluorine is much less abundant than the major bioelements and it is extremely reactive, so whatever fluorine exists, especially at high temperatures, will be combined with the abundant electropositive metals, i.e. mainly with calcium, but also with sodium or aluminum, forming inert minerals, like apatite, criolite, micas etc., not organic molecules or fluoro-silicones.

Personally, I view life as just a self-catalyzing reaction. There seems to be few if any hard rules for life because we seem to always find exceptions. The amount of chemical reactions available is near endless and combined with the sheer number of environments within the universe and there is bound to be other self-catalyzing reactions that could potentially turn into life. There are many reactions that we have no idea even exist because it requires slightly higher or lower pressure or unique atmospheres or environmental conditions that aren't common on Earth, but are common throughout the wider universe.

What is a "self-catalyzing reaction"? Would nuclear fission or fusion count? What about reactions involving free radicals, where the catalyst is a reaction product?

Is the "self-catalyzing reaction" sufficient on its own to classify something as life?

Somewhat related, turns out that it is possible for nuclear reactors to exist naturally in the environment. https://en.wikipedia.org/wiki/Natural_nuclear_fission_reacto...

Makes me feel a bit better about man made nuclear fission if nature has been at it for 2 billion years at that site. (article with photos http://worldkings.org/news/recognized-records/worldkings-the...)

If I recall correctly this is part of the plot to Isaac Asimov's book The God's Themselves. It's always amazing to see how prolific his writing has been.

Does someone know if radiolysis is being researched as a source of commercial hydrogen ( like, for fuel cell vehicle for example ) ? I mean a nuclear reactor might produce heat and hydrogen from radiolysis if I understand correctly ? Is this practical at scale ?

The cave systems are the last frontier of Earth's exploration. We don't actually know the full extent of the cave networks below us.

Deep oceans surely fit the bill as well? We've mapped something like one-fifth of the sea floor.

For sure, but are there caves below the oceans?

to think that some people called the new godzilla movies dumb…

The idea is that the radioactivity produces Hydrogen and Sulfate, and some bacteria (or achaea?) can "burn" the Hydrogen extracting an Oxygen from the Sulfate. So no Godzilla down there.

Unless there are little animals eating the bacteria, and bigger animals eating them, etc.

I mean it's preposterous, but not impossible if for some reason the rock was porous enough. Maybe inside a small moon or asteroid.

There are also radiotrophic fungi found in Chernobyl like Cryptococcus neoformans. [1]

[1] https://en.wikipedia.org/wiki/Radiotrophic_fungus

I'd like to say "nah", but there is a weird case: "The bizarre beasts living in Romania's poison cave" http://www.bbc.com/earth/story/20150904-the-bizarre-beasts-l... (HN discussion https://news.ycombinator.com/item?id=11682816 889 points | May 12, 2016 | 163 comments)

Anyway, in this cave there are snails, shrimps, insects and spiders, but not vertebrates.

The larger animals could eat the rocks and specialized cells lining the stomach would be responsible for converting the energy released from the hydrogen sulfide reactions into an energy pathway like our ATP.

You can't have animals with bones when carbon is naturally lacking, which is exactly what the article says: such areas don't have much carbon in the first place.

Wouldn't you need calcium for bones? Or both?

Anyway there are plenty of animals that don't have bones - and there's no reason to assume our chemical kind of bones are the only kind possible. You could maybe have iron bones evolve on some worlds - I don't know of anything that would prohibit that.

Hollow Earth Theory

*Pourous Earth Theory

I think it's possible that life evolved in two directions. There's sun based evolution and Earth based evolution, because these are the fundamental energy sources for life. Some creatures crawled on land, and some creatures went deeper into the ground. The land creatures evolved into intelligent beings, but we don't know about the others.

If we assume that UFOs and aliens are real, then I think the most likely origin for them is the deep Earth, not space.

By definition, they wouldn’t be aliens then, would they?

Well, depends on how you define it. Another intelligent species which we call 'aliens'.

If there's another industrialized civilization on earth, we would have seen evidence of it.

That's true. However, there wouldn't be much evidence if there's only a relatively small amount of them, or they're really good at hiding their activity. It's also possible that their civilization peaked millions of years ago and they are now mostly existing in some kind of post-biology state, which wouldn't show any signs to the surface.

On Earth, sure.

Inside it, maybe not!

In Dr Who there were green dudes who lived underground on Earth, but they originally came from another planet.

The Silurians were from Earth, IIRC - in the deep past. The end product of the Mesozoic era - intelligent reptiles.

Deep sea chemosynthetic communities, sustained by cycling and release of hydrothermal vent fluids on the seafloor (discovered in the 1970s), are quite unlike anything living at or close to ocean surface, where primary production is sustained by phytoplankton [0]. And bacteria have been found even in extremely deep boreholes [1].

Cold seep chemotrophy exists on the sea floor as well, fueled by reduced gases such as methane, other hydrocarbons (e.g. Gulf of Mexico). But in these seeps, the source of organic carbon may have ultimately come from the sea surface environment.

[0] https://www.whoi.edu/know-your-ocean/ocean-topics/ocean-life... [1] https://www.mdpi.com/2075-1729/10/1/2/htm

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